#![allow(unused_variables)]
#![feature(vec_deque_truncate_front)]
fn main() {
    use std::collections::VecDeque;
    let mut buf = VecDeque::new();
    buf.push_front(5);
    buf.push_front(10);
    buf.push_front(15);
    assert_eq!(buf, [15, 10, 5]);
    assert_eq!(buf.as_slices(), (& [15, 10, 5] [..], & [] [..]));
    buf.truncate_front(1);
    assert_eq!(buf.as_slices(), (& [5] [..], & [] [..]));
}